Improvement in printers  rules



THOMAS S. BOWMAN, OF ST. LOUIS, MISSOURI.

IMPROVEMENT IN PRINTERS RULES.

Specification forming part of Letters Patent No. 1883232, dated March 13, 1877; application tiled December 26, 1876.

To all whom it may concern:

Be it known that I, THOMAS S. BOWMAN,

a resident of St. Louis, Missouri, have made a new and useful Improvement in Printers Mitered Rules, of which the following is a full, clear, and exact description, reference being had to the annexed drawing, making part of this specification, in which Figure 1 is a perspective, showing the two parts of the joint united in position; Figs.2 and 3, views, respectively, of the two parts of the joint; and Fig. 4, another view of one of the parts, looking at the inner side.

Similar letters refer to similar parts.

In a mitered rule, as hitherto made, the bevel at the ends of the. parts forming the miter has extended continuously from the top to the bottom of the rule. This Construction constantly occasions trouble.

In the operation of'locking up, one part of the miter is apt to slip past the other, making an imperfect joint if left in that position. In

endeavoring to force the parts of the rule in tov place'they frequently get bent, and the outer edge of the bevel gets bruised, making the rule defective, it not useless.

mainder of the ends are made square, and in the form of a series of lugs, b b b b b, that are arranged, respectively, on the parts A A, so as to interlock when the joint is formed, as shown in Fig. 1. By this means the principal portions of the ends of the parts A A are brought squarely against each other, and the parts are prevented from slipping upon each other.

The operation of locking up of itself, and without any auxiliary aid, draws the parts together, forming a perfect miter. The interlocking lugs serve to properly direct the parts into position as the form is being fastened, and to prevent the leads that are outside the type matter from entering the joint.

A further advantage accrues from the present improvement-in using fonts of labor-saving rules it is difficult frequently to, make up the miters. They are liable to be slightly incorrect as to length, arising from the difficulty (in the manufacture of the rule) of finishing the outer sharp edge of the bevel at ex actly the right point. 1

My improved miter, having mainly a square end, can be readily and accurately made. Any suitable number of lugs b b can be used.

What I claim is The herein described miter, having the bevels a a and interlocking lugs b b b, substantially as described.

- THOS. S. BOWMAN.

Witnesses:

CHAS. D. MOODY, DANL. T. POTTER 

